Method of constructing abrasive coated cylinders



R. L. DYAR Feb; 27, 1962 METHOD OF CONSTRUCTING ABRASIVE COATED CYLINDERS Filed Aug. 13, 1959 INVENTOR.

ROBERT L. DYAR ATTORNEYS United rates My invention relates to abrasive grating cylinders, and more particularly to a method and apparatus for coating cylinders with an evenly applied quantity of abrasive grain.

One object of my invention is to provide a simple and elfective method of applying an even coat of an adhesive onto the surface of'a cylinder, then applying abrasive grains to the adhesive, and thereafter coating the abrasive with a thin coat of adhesive over the abrasive.

Another object is to provide for removing surplus adhesive applied to the cylinder in a manner that leaves an even coating on the outer peripheral surface of the cylinder.

It is common practice to slid-eably support hollow abrasive cylinders on solid rolls. This is especially true in the processing of vegetables or the like, in the canning industry. Cylinders of various types are employed,

as described in my co-pending application, Serial No.

782,110, filed December 22, 1958, and now abandoned. That application discloses a method for manufacturing the cylinders from a continuous sheet of material which is laminated in spiral fashion to form the desired thickness of wall, and treated in a manner to resist moisture and acids used in the industry. It is the primary object of this invention to provide a method and apparatus for mechanically coating and treating the outer peripheral surface of the cylinders.

Other and further objects of my invention will become more apparent from the following specification and claims, when taken in conjunction with the drawings, in which:

FIGURE 1 is an end view of a cylinder constructed of a single laminated sheet and re-enforced by an adherent agent.

FIGURE 2 is a cross-sectional end view of a reservoir and roller arrangement, and showing a rod for rotatable supporting the cylinder while it is being coated with an adhesive.

FIGURE 3 is a longitudinal cross section taken at the line. 3-3 in FIGURE 2. l

FIGURE 4 is a perspective view of a mandrel for supporting the cylinder while the abrasive is applied.

FIGURE 5 is a longitudinal cross-sectional view of the abrasive hopper with the mandrel in place while the abrasive is applied to the cylinder.

FIGURE 6 is a cross-sectional view of the hopper and mandrel for applying the abrasive taken on the line 6--6 of FIGURE 5. I

FIGURE 7 is a perspective view of the hopper shown in FIGURES 5 and 6.

FIGURE 8 is a partial view of a covered enclosure in cross section and showing the mandrel with the cylinder applied and illustrating the manner in which the surplus adhesive is removed from the cylinder by centrifugal force.

FIGURE 9 is a perspective outer view of the covered enclosure shown in FIGURE 8.

Similar characters of reference indicate corresponding parts throughout the drawings, and referring specifically now to the same, the character 11) shows a cylinder open at both ends and consisting of a sheet of material, such as asbestos, rolled over a mandrel, the sheet material being laminated in spiral fashion and with the several layers joined together by an adherent agent or adhesive such as a phenol formaldehyde resin.

FIGURE 2 illustrates a means for applying adhesive to the roll 10. In FIGURE 2, a body of a liquid adhesive 11 is disposed within '1 reservoir 12. A roller 13 is journalled in bearings 14 and 14 supported by the opposite ends of the reservoir 12 in a manner whereby the roller 13 is partially submerged in the adhesive 11. The adhesive should be of a type that is resistant to water, mild acid and alkali Phenol formaldehyde resin adhesives are satisfactory. A second transfer roller 15 extends across the entire length of the roller 13 and is held in contact therewith at 16 by means of bearings shown as 17 and 17'. A longitudinal roll or shaft 18 is supported at one end 19 in cantilever fashion and extends the entire length of the roller 15 and spaced apart therei from. The bearings 14, 14, 17 and 17' may be supported by arms 12 and 12a which are upstanding from the reservoir 12. In this manner it will become manifest by referring to FIGURE 2 that the roller 13 partially submerged in'the adhesive 11 and when revolved, will cause the adhesive 11 to be carried upward by the roller 13, when the roller 13 is revolved in the direction of the arrow, and come in contact with the peripheral face of the roller 15 and be spread evenly thereon, while causing the roller 15 to revolve in the direction of the arrow.

The shaft 13 is supported on one end only by the arm 12, will permit a laminated cylinder to be disposed thereon, and by offsetting the shaft with respect to the axis of roller and by making shaft 18 of a smaller diameter than the opening in the cylinder 10, the cylinder Ill will contact the top of the rod 18 at 21), and be permitted to rest by gravity on the peripheral face of the coated roller 15. Roller will spread an even coating of the adhesive 11. on the peripheral face of the cylinder 11 when roller 13 is rotated, as bymeans of handle 34.

In FIGURES 5, '6 and 7, I show a container 21 arranged for retaining and supporting a loose bed of abrasive shown as 22 in FIGURE 5. The ends 23 and 23' of the container 21 are shown equipped with bearing members 24 and 24' in the form of vertical! extending slots open at their upper ends 25. The upper edges of the side walls of the container 21 are shown flared outward at 26 to form a hopper.

A mandrel shown in FIGURE 4 consists of a shaft 27 having at one end 28 a recessed flange 29, and having at the other end thereof, a flange 31. It will be noted by referring to FIGURE 6 that the flange 29 is recessed at 32 to a depth such as to accommodate and snugly support the inner wall of the cylinder 10. The flange 36* is of the same diameter as the inner opening of the cylinder 10. Thus the cylinder .10 is frictionally held by the flanges 31 and 32. I

By sliding the cylinder 1% endwise over the flange 31 and onto the recessed flange 29, the cylinder and mandrel assembly may then be placed in position with the shaft ends 28 and 3d engaging the open slots in the bearings 24 and 24 of the container 21 permitting the cylinder or the mandrel to rest by gravity on the surface of the grains of abrasive 22 within the container 21. When the cylinder and mandrel assembly is revolved by meansof a crank 33 attached to the end of the shaft as shown in FIGURE 5, the adhesive will pick up grains from the bed and the same will be distributed substantially uniformly on the surface of the roll it) after several revolutions of the roll Ill.

Obviously the revolving of the shaft 27 in the bearings 24 and 24' may be accomplished in any efficient manner, as by manually turning the crank 33, or by a motor drive. This also applies to rotating the roller 13 in the reservoir 12, which, as shown, is rotated by the crank 34 attached to the outwardly extending portion 35 of the roller 13.

After the cylinder It has been coated with the abrasive, it is removed from mandrel 27 and again coated with an adherent agent of a. thinner viscosity, as by means of apparatus of the type shown in FIGURES 2 and 3. The adhesive for the second coat may be the same type as that used for the first coat. a

In FIGURES 8 and 9, I show an enclosure consisting of a lower portion 35 with a cover member 37 hingedly attached thereto as at 33. If desired, a means of clamping the cover 37 a to the lower portion 36 may be employed, as shown at 39 in FIGURE 8.

The lower portion 36 is shown provided with bearings 40 and 4%)" while the cover member 37 is equipped with bearings 41 and 41' which cooperate with the bearings 46 and 41 in holding the mandrel 2? in place.

The purpose of the hinged enclosure is to permit the abrasive coated cylinder 10 mounted onto the mandrel 27 to be placed on the bearings 49 and 4t} and clamped by the bearings 41 and 41' in the cover 3'2 when the cover 37 is lowered into position. The cylinder 10 may be revolved rapidly thereby causing the surplus adhesive applied in the second coating over the abrasive to be removed by centrifugal force as shown by the arrows 42.

From the above description it will be seen that the cylinder is coated with adhesive as described and shown in FIGURES 2 and 3, coated with abrasive grain as shown in FIGURES 5 and 6, and coated with a second coat of adhesive over the abrasive grains, and has the surplus adhesive removed from its surface by centrifugal force as shown in FIGURE 8.

In carrying out the method of the present invention, the practitioner, after forming a cylindrical backing roll, as illustrated at 16 in FIGURE 1, coats the external peripheral surface of the cylinder with adhesive, as is illustrated in FIGURE 2. The coating so applied should completely cover the peripheral surface of the cylinder and have a thickness consistent with the amount of abrasive desired on the cylinder. For relatively fine grains'of abrasive, the initial coating may be relatively thin, whereas with larger grains, the coating can be more thick.

Before the adhesive forming the first coating has set, the cylinder 10 is impressed with abrasive grains as in FIGURES 5 and 6. The rolling contact of the adhesive coated cylinder when supported on the bed of abrasive grains is ordinarily suflicient to entirely coat the surface of the cylinder with grains. The grains are thereby pressed into the adhesive and after one or more revolutions of the cylinder on the bed of abrasive grains, the grains will overlie the initial coating and protrude from the surface of the coating to some extent.

While ordinarily it is preferred to subject the cylinder to the bed of abrasive grains immediately after coating the cylinder, the cylinder can be placed on the bed of abrasive grains while the adhesive forming the first coating is still tacky. In other words, some delay of time is permissible between the coating of the cylinder with adhesive and the impressing of the abrasive grains thereon.

It is advantageousto heat the coat cylinder so as to partially or fully cure the adhesive and fix the abrasive grains. The temperatures used may vary to suit the adhesive used.

After covering the cylinder with the abrasive grains, and the first coating is at least partially cured, the roller is then given a second coating of adhesive which may be the same adhesive used in the initial coating step, such as, for example, phenol formaldehyde resin although the adhesive in the second coating must be of thinner'viscosity than the adhesive coating in the first coating step. An appropriate thinning agent may be used with the adhesive to accomplish this end Where needed. The viscosity of the adhesive in the second coating should be such that it fills the spaces between the protruding or overlying grains of abrasive while substantially covering the abrasive grains. The second coat of adhesive must, however, be suiiiciently thin as to enable the removal of excess adhesive by centrifugal action in the subsequent portion of the method.

After the second coating of adhesive has been applied, excess adhesive is removed by the centrifugal action illustrated in FIGURE 8. The speed of rotation may be widely varied, although generally, rotational speeds of 150 to 800 rpm. are satisfactory in removing excess. For lower speeds, the second adhesive coating should be thinner while for higher speeds the second adhesive coating can be thicker. The thickness of the second coating and the rotational speed should be such that excess adhesive which overlies and covers the grains is removed by the centrifugal action.

The adhesive is then cured as, for example, by means I of heat to fully cure the adhesive in both coats.

The end result is an abrasive coated cylinder with abrasive grains anchored to the surfaceof the cylinder which may, for example, be formed of sheet asbestos, with the grains re-enforced by the second coating of adhesive. The adhesive from the second coating fills spaces between the grains, which spaces are left after the first coating has been impressed with the grains.

Obviously, various sizes of abrasive particles can be used in the process, as long as they are of such size that they will adhere to the initial coating of adhesive when the cylinder is placed in gravitational contact with the bed of abrasive particles or grains.

Whereas I have shown and described an operative form of the invention, it should be understood that this showing and description thereof are to be taken in an illustrative or diagrammatic sense only. There are many modifications to the invention which will fall within the scope and spirit thereof and which will be apparent to those skilled in the art. The scope of the invention should be limited only by the scope of the hereinafter appended claims.

I claim:

1. The method of applying a reinforcing coating of adhesive material to abrasive grains adhesively carried on the peripheral surface of a cylinder including the steps of applying a coating of adhesive material, after an initial coating of grain holding adhesive has at least partially cured, to'the peripheral face of the grain carrying cylinder with adhesive material so applied filling the spaces between grains and covering some of the grains, then rotating the so coated cylinder at a speed such, with relation to the viscosity of the adhesive material as to expel excess adhesive material which overlies and covers the grains by centrifugal force while leaving a reinforcing layer of adhesive material from said second coating between the grains, and then allowing the adhesive material to cure.

2. A method for applying an abrasive coating to the external peripheral face of a cylinder including the steps of applying a first coating of adhesive material to the peripheral face of a cylinder, impressing abrasive grains in said adhesive material, allowing said first coating to at least partially cure, then applying 'a second coating of adhesive material to the grain carrying face of the cylinder, the adhesive material of said second coating having a viscosity such as to substantially fill the spaces between said grains while covering some of the grains and allowing removal of excess adhesive by centrifugal force, and then rotating the cylinder at a speed such, with relation to the viscosity of the adhesive material in said second coating as to expel excess adhesive which overlies and covers the grains by centrifugal force while leaving a reinforcing coating of adhesive from said second coating between the grains, and then allowing the adhesive material to cure.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS 6 Cross May 5, 1942 DiCesare June 9, 1942 Blackburn Nov. 15, 1949 Thomas Dec. 13, 1949 Nichols Nov. 15, 1955 Isler Dec. 6, 1955 Edgecombe et a1. Aug. 20, 1957 Johnson Aug. 30, 1960 FOREIGN PATENTS Great Britain Ian. 21, 1953 

1. THE METHOD OF APPLYING A REINFORCING COATING OF ADHESIVE MATERIAL TO ABRASIVE GRAINS ADHESIVELY CARRIED ON THE PERIPHERAL SURFACE OF A CYLINDER INCLUDING THE STEPS OF APPLYING A COATING OF ADHESIVE MATERIAL, AFTER AN INITIAL COATING OF GRAIN HOLDING ADHESIVE HAS AT LEAST PARTIALLY CURED, TO THE PERIPHERAL FACE OF THE GRAIN CARRYING CYLINDER WITH ADHESIVE M,ATERIAL SO APPLIED FILLING THE SPACES BETWEEN GRAINS AND COVERING SOME OF THE GRAINS, THEN 